Rainwater Harvesting

• Rainwater harvesting is the accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off. Rainwater can be collected from rivers or roofs, and in many places, the water collected is redirected to a deep pit (well, shaft, or borehole), a reservoir with percolation, or collected from dew or fog with nets or other tools. Its uses include water for gardens, livestock, irrigation, domestic use with proper treatment, indoor heating for houses, etc. The harvested water can also be used as drinking water, longer-term storage, and for other purposes such as groundwater recharge.
• The harvesting of rainwater simply involves the collection of water from surfaces on which rain falls, and subsequently storing this water for later use. Normally water is collected from the roofs of buildings and stored in rainwater tanks. This is very common in rural Australia. Water can also be collected in dams from rain falling on the ground and producing runoff.

History

The technology of rainwater harvesting system during the ancient days can still be found today in India. These includes;
• Talibs (a medium to large sizes reservoirs that provide irrigation for plants as well as drinking)
• Johads (dams that are used to capture and keep rainwater)
• Baoris(wells dug into the ground that are often still used for drinking)
• Jhalaras (specially constructed tanks that are used for the local community and religious purposes).

Roman Empire
During the Roman Empire, rainwater collection became an art and science, with many new cities incorporating state of the art technology for the time. The Romans were masters at these new developments and great progress was made right up until the 6th Century AD and the rule of Emperor Caesar.

One of the most impressive rainwater harvesting constructions can be found in Istanbul in the Sunken Palace which was used to collect rainwater from the streets above.

When Byzantium became Constantinople (now known as Istanbul) became the main imperial residence for the Roman Empire, more inhabitants occupied the city. So, large cisterns were built to store water. One of them was the Basilica Cistern or, as it is called today.